Nitrile derivatives as perfuming ingredients

ABSTRACT

The present invention concerns substituted benzylic nitrites substituted with lower linear alkyl or alkylene groups. These compounds are useful perfuming ingredients, and can impart odor notes of the floral-green type. The invention concerns also the perfuming compositions or perfumed articles associated with the compound.

TECHNICAL FIELD

The present invention relates to the field of perfumery. More particularly, it concerns substituted benzylic nitrites which are useful as perfuming ingredients, in particular to impart odor notes of the floral-green type.

BACKGROUND

Amongst the compounds of formula (I), as defined below, a few are known. In particular, all the compounds wherein the dotted line represents a double bond have been previously described for various purposes such as chemical intermediates (for example: α-butylidene-benzeneacetonitrile has been reported by S. I. Murahashi et al. in Synlett, 2000, 1016). However, none of the prior art documents disclosing a compound of formula (I) reports or suggests any organoleptic properties of the invention's compounds, or any use of these compounds in the field of perfumery.

The compounds described in EP application 682010 or in U.S. Pat. No. 6,069,125 are the known perfuming ingredients having the closest structure to the invention's compounds. However, the invention's compounds not only differ from the prior art compounds in their chemical structure but also in the organoleptic properties which are, in the case of the prior art, of the of the marine or rosy-fruity (sweet) type. Nowhere in these two patents there is a suggestion of any usefulness of the invention's compounds in the field of perfumery, and even less of any organoleptic properties of the present compounds.

SUMMARY OF THE INVENTION

The present invention now relates to the use as perfuming ingredients of a particular benzylic nitrile as well as to the perfuming compositions or the perfumes articles containing the invention's nitrile. Furthermore the invention relates also to a new method for the preparation of benzylic nitrites.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

We have now surprisingly discovered that a compound of formula

wherein R¹ is a C₁₋₄ linear alkyl group, and

-   -   a) the dotted line represents a double bond having a         configuration E or Z or a mixture thereof, and R² is a hydrogen         atom; or     -   b) the dotted line represents a single bond, and R² is a C₁₋₄         linear alkyl group;         can be used as perfuming ingredient, for instance to impart odor         notes of the floral type.

According to a particular embodiment of the invention, R¹ represents a C₂-C₃ linear alkyl group, and in particular a n-propyl group.

According to any of the above mentioned embodiments, the compounds wherein the dotted line represents a double bond are preferred, and in particular those having this double bond in a configuration essentially Z, i.e. the Z isomer representing at least 90% relative to the weight of the mixture.

Amongst the compounds of formula (I) those wherein the dotted line represents a single bond and

-   i) R¹ is a C₃₋₄ linear alkyl group and R² is a methyl group; or -   ii) R¹ is a C₁₋₄ linear alkyl group and R² is a C₂₋₄ linear alkyl     group     are new and are an object of the present invention.

Amongst the compounds of formula (I), one may cite in particular, and as non-limiting example, (2Z)-2-phenyl-2-hexenenitrile. This compound has a substantive and powerful floral, green-floral, odor with jasmine-muguet, lilac, herbal-lavender-rosemary notes. The overall odor of this compound has a strong hexylcinnamic aldehyde connotation (i.e. herbaceous-floral) and is also slightly green-geranium (e.g. of the diphenyl oxide type). The odor of the invention's compound has also bottom notes presenting amyl salicilate and chocolate aspects.

More interesting, this compound can also display citrus or citronella notes depending on the medium into which it is incorporated, as will be further illustrated in the examples.

When compared to the prior art compound 2-phenyl-2-hexanenitrile (see EP application 682010) the invention's compound distinguishes by lacking, or by not possessing significant, anethole/carvone-like undernotes, as well as by lacking, or by not possessing significant, fruity (pineapple) and rosy note notes which are characteristic of the prior art compound. This difference lends to (2Z)-2-phenyl-2-hexenenitrile and 2-phenyl-2-hexanenitrile to be each suitable for different uses, i.e. to impart different organolpetic impressions.

Another example of invention's compound is 2-(4-methylphenyl)hexanenitrile which possesses an odor with floral-jasmine and geranium notes as well as nitrilic and fruity notes. The overall scent is close to the fragrance of hexylcinnamic aldehyde.

Yet another example of invention's compound is 2-(4-ethylphenyl)pentanenitrile which is characterized by a nice florale-jasminic and hyacinth note having also a coumarine aspect. The bottom notes of this compound reminds of the odor of hexylcinnamic aldehyde.

These last two compounds named do not have or are almost devoid of a particular fruity or rosy connotation, to the contrary of 2-phenyl-2-hexanenitrile (see EP application 682010)

Amongst the compounds of formula (I), (2Z)-2-phenyl-2-hexenenitrile and 2-(4-methylphenyl)hexanenitrile are the preferred ones.

As mentioned above, the invention concerns the use of a compound of formula (I) as perfuming ingredients. In other words it concerns a method to confer, enhance, improve or modify the odor properties of a perfuming composition or of a perfumed article, which method comprises adding to the composition or article an effective amount of at least a compound of formula (I). By “use of a compound of formula (I)” it has to be understood here also the use of any composition containing compound (I) and which can be advantageously employed in perfumery industry as active ingredients.

These compositions, which are in fact perfuming compositions that can be advantageously employed as perfuming ingredients, are also an object of the present invention.

Therefore, another object of the present invention is a perfuming composition comprising:

-   i) as a perfuming ingredient, at least one inventive compound as     defined above; -   ii) at least one ingredient selected from the group consisting of a     perfumery carrier and a perfumery base; and -   iii) optionally at least one perfumery adjuvant.

By “perfumery carrier” we mean here a material which is practically neutral from a perfumery point of view, i.e. that does not significantly alter the organoleptic properties of perfuming ingredients. This carrier may be a liquid or a solid.

As liquid carrier one may cite, as non-limiting examples, an emulsifying system, i.e. a solvent and a surfactant system, or a solvent commonly used in perfumery. A detailed description of the nature and type of solvents commonly used in perfumery cannot be exhaustive. However, one can cite as non-limiting examples solvents such as dipropyleneglycol, diethyl phthalate, isopropyl myristate, benzyl benzoate, 2-(2-ethoxyethoxy)-1-ethanol or ethyl citrate, which are the most commonly used.

As solid carrier one may cite, as non-limiting examples, absorbing gums or polymers, or yet encapsulating materials. Examples of such materials, for example, may comprise wall-forming and plasticizing materials, such as mono, di- or trisaccharides, natural or modified starches, hydrocolloids, cellulose derivatives, polyvinyl acetates, polyvinylalcohols, proteins or pectins, or yet the materials cited in reference texts such as H. Scherz, Hydrokolloids: Stabilisatoren, Dickungs- und Gehermittel in Lebensmittel, Band 2 der Schriftenreihe Lebensmittelchemie, Lebensmittelqualitat, Behr's VerlagGmbH & Co., Hamburg, 1996. The encapsulation is a well known process to a person skilled in the art, and may be performed, for instance, using techniques such as spray-drying, agglomeration or yet extrusion; or consists of a coating encapsulation, including coacervation and complex coacervation techniques.

Generally speaking, by “perfumery base” we mean here a composition comprising at least one perfuming co-ingredient.

This perfuming co-ingredient is not of the formula (I). Moreover, by “perfuming co-ingredient” it is meant here a compound, which is used in perfuming preparation or composition to impart a hedonic effect. In other words such a co-ingredient, to be considered as being a perfuming one, must be recognized by a person skilled in the art as being able to impart or modify in a positive or pleasant way the odor of a composition, and not just as having an odor.

The nature and type of the perfuming co-ingredients present in the base do not warrant a more detailed description here, which in any case would not be exhaustive, the skilled person being able to select them on the basis of its general knowledge and according to intended use or application and the desired organoleptic effect. In general terms, these perfuming co-ingredients belong to chemical classes as varied as alcohols, aldehydes, ketones, esters, ethers, acetates, nitrites, terpene hydrocarbons, nitrogenous or sulphurous heterocyclic compounds and essential oils, and the perfuming co-ingredients can be of natural or synthetic origin. Many of these co-ingredients are in any case listed in reference texts such as the book by S. Arctander, Perfume and Flavor Chemicals, 1969, Montclair, N.J., USA, or its more recent versions, or in other works of a similar nature, as well as in the abundant patent literature in the field of perfumery. It is also understood that these co-ingredients may also be compounds known to release in a controlled manner various types of perfuming compounds.

Generally speaking, by “perfumery adjuvant” we mean here an ingredient capable of imparting additional added benefit such as a color, a particular light resistance, chemical stability, etc. A detailed description of the nature and type of adjuvant commonly used in perfuming bases cannot be exhaustive, but it has to be mentioned that these ingredients are well known to a person skilled in the art.

An invention's composition consisting of at least one compound of formula (I) and at least one perfumery carrier represents a particular embodiment of the invention as well as a perfuming composition comprising at least one compound of formula (I), at least one perfumery carrier, at least one perfumery base, and optionally at least one perfumery adjuvant.

It is useful to mention here that the possibility to have, in the compositions mentioned above, more than one compound of formula (I) is important as it enables the perfumer to prepare accords, perfumes, possessing the odor tonality of various compounds of the invention, creating thus new tools for their work.

Its is also understood here that, unless otherwise indicated or described, any mixture resulting directly from a chemical synthesis, e.g. without an adequate purification, in which the compound of the invention would be involved as a starting, intermediate or end-product could not be considered as a perfuming composition according to the invention.

Furthermore, the invention's compound can also be advantageously used in all the fields of modern perfumery to positively impart or modify the odor of a consumer product into which the compound (I) is added. Consequently, a perfumed article comprising:

-   i) as perfuming ingredient, at least one compound of formula (I) as     defined above; and -   ii) a consumer product base,     is also an object of the present invention.

For the sake of clarity, it has to be mentioned that, by “consumer product base” we mean here a consumer product which is compatible with perfuming ingredients. In other words, a perfumed article according to the invention comprises the functional formulation, as well as optionally additional benefit agents, corresponding to a consumer product, e.g. a detergent or an air freshener, and an olfactive effective amount of at least one invention's compound.

The nature and type of the constituents of the consumer product do not warrant a more detailed description here, which in any case would not be exhaustive, the skilled person being able to select them on the basis of its general knowledge and according to the nature and the desired effect of the product.

Examples of suitable consumer products include solid or liquid detergents and fabric softeners as well as all the other articles common in perfumery, namely perfumes, colognes or after-shave lotions, perfumed soaps, shower or bath salts, mousses, oils or gels, hygiene products or hair care products such as shampoos, body-care products, deodorants or antiperspirants, air fresheners and also cosmetic preparations. As detergents there are intended applications such as detergent compositions or cleaning products for washing up or for cleaning various surfaces, e.g. intended for textile, dish or hard-surface treatment, whether they are intended for domestic or industrial use. Other perfumed articles are fabric refreshers, ironing waters, papers, wipes or bleaches.

It has to be mentioned that the invention's compounds, due to their chemical structure, which renders them quite resistant to many aggressive medium, are particularly suitable for the preparation of perfuming composition for the functional perfumery.

The proportions in which the compounds according to the invention can be incorporated into the various aforementioned articles or compositions vary within a wide range of values. These values are dependent on the nature of the article to be perfumed and on the desired organoleptic effect as well as the nature of the co-ingredients in a given base when the compounds according to the invention are mixed with perfuming co-ingredients, solvents or additives commonly used in the art.

For example, in the case of perfuming compositions, typical concentrations are in the order of 0.001% to 15% by weight, or even more, of the compounds of the invention based on the weight of the composition into which they are incorporated. Concentrations lower than these, such as in the order of 0.01% to 10% by weight, can be used when these compounds are incorporated into perfumed articles.

The compounds of formula (I) can be synthesized by a new and original process, which is also an object of the present invention.

The inventive process is particularly useful for the preparation of a compound of formula

wherein R³ and R⁴ represent, independently from each other, a hydrogen atom or a C₁₋₄ linear alkyl or alkoxy group, and R⁵ represents a C ₁₋₈ linear or branched alkyl; by reacting a nitrile of formula

wherein R³ and R⁴ have the meaning indicated above; with an alcohol of formula R⁵′CH₂OH, wherein R⁵′ represents a C₁₋₈ linear or branched alkyl or alk-2-enyl; in the presence of a catalytic system, the process being characterized in that the reaction temperature is above 100° C. and the catalytic system is a mixture comprising a base, having a pK_(a) above 13, and a complex selected from the group consisting of [RuCl₂(p-cym)]₂ and [RuCl₂(p-cym)(PPh₃)], p-cym meaning p-cymene.

When R⁵, in formula R⁵CH₂OH, represents an alkyl group then there is obtained a compound of formula (II) wherein the dotted line represents a single bond. When R⁵, in formula R⁵CH₂OH, represents an alk-2-enyl group then there is obtained a compound of formula (II) wherein the dotted line represents a double bond.

The complex is generally used in an amount ranging from 0.001 to 0.01 molar equivalent relative to the amount of compound of formula (III).

Typical examples of base useful for the invention's process are KOH, NaOH or DBU. Moreover, preferably, the base is present in an amount of about 5 to 15 molar equivalents relative to the amount of the complex.

Furthermore, in the process the alcohol R⁵CH₂OH may advantageously be used as solvent, i.e. in a large excess compared to the amount of compound of formula (III).

Preferably, the compounds of formula (II) are those of formula (I).

EXAMPLES

The following examples are further illustrative of the present invention's embodiments, and further demonstrate the advantages of the invention relative to the prior art teachings. In the following examples, the abbreviations have the usual meaning in the art, the temperatures are indicated in degrees centigrade (° C.); the NMR spectral data were recorded in CDCl₃ (if not stated otherwise) with a 400 or 100 MHz machine for ¹H or respectively ¹³C, the chemical displacements δ are indicated in ppm with respect to TMS as standard, the coupling constants J are expressed in Hz.

Example 1 Synthesis of Compounds of Formula (I) According the Invention's Process

a) Preparation of (2Z)-2-phenyl-2-hexenenitrile

A 500 ml three necked flask equipped with a magnetic stirring bar and an argon inlet-outlet, was charged with benzylnitrile (17.6 g, 150 mmol), crotyl alcohol (86.54 g, 1.2 mol, trans/cis mixture: 23/1), potassium hydroxide (420.9 mg, 7.5 mmol) and [RuCl₂(p-cym)]₂ (229.8 mg, 0.38 mmol). The flask was then evacuated, back filled with argon and heated at 100° C. for 1.5 hour. When the reaction was terminated, the reaction mixture was cooled and poured into water (500 ml), extracted with AcOEt (3×100 ml). The organic phases were dried over anhydrous MgSO₄, filtered and the solvent was removed in vacuo. Distillation under reduced pressure gave the desired nitrile with a yield of 45%.

¹H-NMR analysis of this mixture showed also that nitrile was present as a mixture of two diastereomers (Z/E=95/5).

B.p.: 121-123° C. /5.4 mbar ¹³C NMR: 146.9 (d), 133.3 (s), 128.9 (d), 128.8 (d), 125.6 (d), 116.7 (s, CN), 116.1 (s), 34.1 (t), 22.0 (t), 13.7 (q).

¹H NMR: 7.54-7.50 (m, 2H), 7.40-7.30 (m, 3H), 6.82 (t, J=7.7, 1H), 2.56 (dt, J=7.7, 7.2, 2H), 1.59 (sext, J=7.2, 2H), 1.01 (t, J=7.2, 3H).

b) Preparation of 2-(4-methylphenyl)hexanenitrile

A 500 ml three necked flask equipped with a magnetic stirring bar and an argon inlet-outlet, was charged with 4-methylbenzylcyanide (19.73 g, 150 mmol), 1-propanol (89.1 g, 1.2 mol), potassium hydroxide (423.5 mg, 7.5 mmol) and [RuCl₂(p-cym)]₂ (232.6 mg, 0.375 mmol). The flask was then evacuated, back filled with argon and heated at 100° C. for 1 hour. When the reaction was terminated, the reaction mixture was cooled to room temperature and concentrated in vacuo. The residue was taken into Et₂O (500 ml) and washed with water (3×50 ml). The organic phase was dried over anhydrous MgSO₄, filtered and the solvent was removed in vacuo. Distillation under reduced pressure gave the desired nitrile with a yield of 70%.

B.p.: 105-106° C. /1.3 mbar.

¹³C NMR: 137.7 (s), 133.1 (s), 129.7 (d), 127.1 (d), 121.1 (s, CN), 36.9 (d), 35.6 (t), 29.1 (t), 22.1 (t), 21.0 (q), 13.8 (q).

¹H NMR: 7.19 (AB syst. J_(AB)=8.2, 4H), 3.72 (dd, J=8.4, 6.4, 1H), 2.34 (s, 3H), 1.95-1.78 (m, 2H), 1.52-1.29 (m, 4H), 0.89 (t, J=7.2, 3H).

c) Preparation of 2-(4-ethylphenyl)pentanenitrile

Following the same procedure given in b), 4-ethylbenzylcyanide (5.08 g, 35 mmol), 1-propanol (21 ml, 280 mmol) were reacted with potassium hydroxide (99.1 mg, 1.75 mmol) and [RuCl₂(p-cym)]₂ (55.1 mg, 0.09 mmol) at 100° C. for 1 h. Removal of the solvent and distillation under reduced pressure gave the desired nitrile with a yield of 51%.

B.p.: 74-75° C. /0.2 mbar.

¹³C NMR: 144.1 (s), 133.3 (s), 128.5 (d), 127.2 (d), 121.1 (s, CN), 37.9 (t), 36.8 (d), 28.5 (t), 20.3 (t), 15.5 (q), 13.4 (q).

¹H NMR: 7.21 (AB syst. J_(AB)=8.4, 4H), 3.74 (dd, J=8.4, 6.4, 1H), 2.64 (q, J=7.7, 2H), 1.95-1.76 (m, 2H), 1.58-1.42 (m, 2H), 1.23 (t, J=7.7, 3H), 0.95 (t, J=7.2 Hz, 3H).

Example 2 Preparation of a Perfuming Composition

A perfuming composition for a “Savon de Marseille” was prepared by admixing the following ingredients Parts Ingredient by weight Verdyl acetate 100 Hexyl acetate 20 3-Methyl-2-hexenyl acetate¹⁾ 10 Aldehyde C 12 25 Aldehyde Hexylcinnamique 100 Aldehyde MNA 20 Aldehyde Supra 10 Allyl amyl glycolate 20 Ethyl 2-methyl-pentanoate¹⁾ 15 CETALOX ®²⁾ 10 Citral diethylacetal 25 Cyclopentol 30 Damascone Alpha 5 Damascenone Total¹⁾ 5 Dihydro Eugenol 10 Dihydromyrcenol 200 Ethyle-2-methylbutytate 5 Eucalyptus essential oil 15 Eugenol 40 GALAXOLIDE ® 50% MIP³⁾ 100 Geranyl Nitrile 50 HEDIONE ®⁴⁾ 60 Ionone beta 40 IRALIA ® Total⁵⁾ 150 Iso E Super ®⁶⁾ 400 LILIAL ®⁷⁾ 200 Linalol 150 10%* 2,6-Dimethyl-5-heptanal 5 Methylnaphthylcetone 40 Methylparacresol 5 Muscenone⁸⁾ 50 MYROXYDE ®⁹⁾ 10 10%* Neobutenone ®¹⁰⁾ 20 NIRVANOL ®¹¹⁾ 30 Trans-1-(2,2,6-trimethyl-1-cyclohexyl)-3-hexanol¹⁾ 10 Paracymene 30 Phenethylol 150 10%* ROMASCONE ®¹²⁾ 30 SCLAREOLATE ®¹³⁾ 100 Terpene Orange 100 2,4-Dimethyl-3-cyclohexen-1-carboxaldehyde 10 Undecalactone 50 VERDOX ®¹⁴⁾ 100 (E)-1-(2,6,6-Trimethyl-1- 60 cyclohexen-1-yl)-1-penten-3-one 2615 *in dipropyleneglycol ¹⁾Origin: Firmenich SA, Geneva, Switzerland ²⁾Dodecahydro-3a,6,6,9a-tetramethyl-naphtho[2,1-b]furan; origin: Firmenich SA, Geneva, Switzerland ³⁾1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethyl-cyclopenta-g-2-benzopyrane; origin International Flavors & Fragrances, USA ⁴⁾Methyl dihydrojasmonate; origin: Firmenich SA, Geneva, Switzerland ⁵⁾Mixture of isomers of methylionones; origin: Firmenich SA, Geneva, Switzerland ⁶⁾1-(Octahydro-2,3,8,8-tetramethyl-2-naphthalenyl)-1-ethanone; origin International Flavors & Fragrances, USA ⁷⁾3-(4-tert-Butylphenyl)-2-methylpropanal; origin: International Flavors & Fragrances, USA ⁸⁾3-Methyl-4/5-cyclopentadecen-1-one; origin: Firmenich SA, Geneva, Switzerland ⁹⁾6,7-Epoxy-3,7-dimethyl-1,3-octadiene; origin: Firmenich SA, Geneva, Switzerland ¹⁰⁾1-(5,5-Dimethyl-1-cyclohexen-1-yl)-4-penten-1-one; origin: Firmenich SA, Geneva, Switzerland ¹¹⁾3,3-Dimethyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)-4-penten-2-ol; origin: Firmenich SA, Geneva, Switzerland ¹²⁾Methyl 2,2-dimethyl-6-methylene-1-cyclohexanecarboxylate; origin: Firmenich SA, Geneva, Switzerland ¹³⁾Propyl (S)-2-(1,1-dimethylpropoxy)propanoate; origin: Firmenich SA, Geneva, Switzerland ¹⁴⁾2-tert-Butyl-1-cyclohexyl acetate; origin: International Flavors & Fragrances, USA

The addition of 300 parts by weight of (2Z)-2-phenyl-2-hexenenitrile to the above-described perfuming composition provided a new composition which had a fragrance more functional, detergent-like. Moreover the new composition had a reinforced green-citronella connotation. Furthermore, when linen was washed with a detergent containing the new composition, the linen after drying had a powerful salicylate note, of the floral-herbaceous type, which was totally absent from a linen washed with a detergent containing the composition not containing the invention's compound.

This connotation/note was lacking pineapple and rosy character.

Example 3 Preparation of a Perfuming Composition

A perfuming base for a soap was prepared by admixing the following ingredients: Parts Ingredient by weight Verdyl acetate 200 Anisic aldehyde 270 Aldehyde C 10 20 10-Undecenal 30 Aldehyde C 12 60 Aldehyde MNA 50 Methyl benzoate 60 Benzylacetone 250 CETALOX ®¹⁾ 50 Citronnelle Java 1000 Dodecanenitrile 40 Coumarine 130 Cyclopidene²⁾ 60 (1′R,E)-2-Ethyl-4-(2′,2′,3′-trimethyl-3′-cyclopenten- 90 1′-yl)-2-buten-1-ol Dihydromyrcenol 350 Diphenyloxyde 1000 Ethylvanilline 30 Eucalyptol 100 Eugenol 90 GALAXOLIDE ® 50% MIP³⁾ 250 3-(3-Isopropyl-1-phenyl)butanal 50 Geranyl Nitrile 90 HABANOLIDE ®⁴⁾ 300 Ionone beta 180 IRALIA ® Total⁵⁾ 400 ISO E SUPER ®⁶⁾ 600 LILIAL ®⁷⁾ 650 Linalol 350 LORYSIA ®⁸⁾ 300 Methylnaphthylcetone 180 Methylparacresol 90 NIRVANOL ®⁹⁾ 30 Trans-1-(2,2,6-trimethyl-1-cyclohexyl)-3-hexanol²⁾ 30 Phenethylol 450 Phenylhexanol 450 Verdyl propionate 200 Terpinolene 450 Undecalactone gamma 150 POLYWOOD ®¹⁰⁾ 70 10%* Methyl octinecarbonate 30 LIMINAL ®¹¹⁾ 100 9280 *in dipropyleneglycol ¹⁾Dodecahydro-3a,6,6,9a-tetramethyl-naphtho[2,1-b]furan; origin: Firmenich SA, Geneva, Switzerland ²⁾Origin: Firmenich SA, Geneva, Switzerland ³⁾1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethyl-cyclopenta-g-2-benzopyrane; origin International Flavors & Fragrances, USA ⁴⁾Pentadecenolide; origin: Firmenich SA, Geneva, Switzerland ⁵⁾Mixture of isomers of methylionones; origin: Firmenich SA, Geneva, Switzerland ⁶⁾1-(Octahydro-2,3,8,8-tetramethyl-2-naphthalenyl)-1-ethanone; origin International Flavors & Fragrances, USA ⁷⁾3-(4-tert-Butylphenyl)-2-methylpropanal; origin: International Flavors & Fragrances, USA ⁸⁾4-(1,1-Dimethylethyl)-1-cyclohexyl acetate; origin: Firmenich SA, Geneva, Switzerland ⁹⁾3,3-Dimethyl-5-(2,2,3-trimethyl-3-cyclopenten-1-yl)-4-penten-2-ol; origin: Firmenich SA, Geneva, Switzerland ¹⁰⁾Perhydro-5,5,8aa-trimethyl-2a-trans-naphthalenyle acetate; origin: Firmenich SA, Geneva, Switzerland ¹¹⁾3-(4-Tert-butylphenyl)-2-methylpropanal; origin: Givaudan-Roure SA, Vernier, Switzerland

The addition of 150 parts by weight of (2Z)-2-phenyl-2-hexenenitrile to the above-described perfuming base imparted to the fragrance of the latter a clear floral-jasmine and salicylate connotation slightly green and cosmetic. This connation was lacking pineapple and rosy character. 

1. A method to confer, enhance, improve or modify the odor properties of a perfuming composition or of a perfumed article, which method comprises adding to the composition or article an effective amount of at least a compound of formula

wherein R¹ is a C₁₋₄ linear alkyl group, and a) the dotted line represents a double bond having a configuration E or Z or a mixture thereof, and R² is a hydrogen atom; or b) the dotted line represents a single bond, and R² is a C₁₋₄ linear alkyl group.
 2. A method according to claim 1, wherein in formula (I) R¹ represents a C₂-C₃ linear alkyl group.
 3. A method according to claim 2, wherein in formula (I) the dotted line represents a double bond having a configuration Z.
 4. A method according to claim 3, wherein the compound is selected from the group consisting of (2Z)-2-phenyl-2-hexenenitrile and 2-(4-methylphenyl)hexanenitrile.
 5. A perfuming composition comprising: i) at least a compound of formula (I), as defined in claim 1; ii) at least one ingredient selected from the group consisting of a perfumery carrier and a perfumery base; and iii) optionally at least one perfumery adjuvant.
 6. A perfumed article comprising: i) at least one compound of formula (I), as defined in claim 1; and ii) a consumer product base.
 7. A perfumed article according to claim 6, wherein the consumer product base is a solid or liquid detergent, a fabric softener, a perfume, a cologne or after-shave lotion, a perfumed soap, a shower or bath salt, mousse, oil or gel, a hygiene product, a hair care product, a shampoo, a body-care product, a deodorant or antiperspirant, an air freshener, a cosmetic preparation, a fabric refresher, an ironing water, a paper, a wipe or a bleach.
 8. A compound of formula

wherein the dotted line represents a single bond and i) R¹ is a C₃₋₄ linear alkyl group and R² is a methyl group; or ii) R¹ is a C₁₋₄ linear alkyl group and R² is a C₂₋₄ linear alkyl group.
 9. As a compound according to claim 8, 2-(4-methylphenyl)hexanenitrile or 2-(4-ethylphenyl)pentanenitrile.
 10. A process for the preparation of a compound of formula

wherein R³ and R⁴ represent, independently from each other, a hydrogen atom or a C₁₋₄ linear alkyl or alkoxy group, and R⁵ represents a C₁₋₈ linear or branched alkyl; by reacting a nitrile of formula

wherein R³ and R⁴ have the meaning indicated above; with an alcohol of formula R⁵′ CH₂OH, wherein R⁵′ represents a C ₁₋₈ linear or branched alkyl or alk-2-enyl; in the presence of a catalytic system, the process being characterized in that the reaction temperature is above 100° C. and the catalytic system is a mixture comprising a base having a pKa above 13 and a complex selected from the group consisting of [RuCl₂(p-cym)]₂ and [RuCl₂(p-cym)(PPh₃)], p-cym meaning p-cymene. 